The present invention relates generally to new and novel interconnected vents for a motor vehicle axle assembly, transmission or transfer case. More particularly, the present invention relates to new and novel interconnected vents for a motor vehicle axle assembly, transmission or transfer case which captures, retains and returns lubricant to the motor vehicle axle assembly, transmission or transfer case and precludes lubricant from flowing out of a vent onto the ground.
During operation, the lubricant in motor vehicle axle assemblies, transmissions and transfer cases generally becomes warmer and, therefore, expands. If no vent is provided in the motor vehicle axle assembly, transmission or transfer case, such lubricant expansion can cause a significant pressure increase and undesirable consequences. Furthermore, when operation of the motor vehicle axle assembly, transmission or transfer case ends, the lubricant will cool, thus creating a pressure decrease in the motor vehicle axle assembly, transmission or transfer case cavity.
Accordingly, a vent in an upper portion of the motor vehicle axle assembly, transmission or transfer case cavity is normally provided to equalize the pressure in the motor vehicle axle assembly, transmission or transfer case cavity with the outside environment. However, such vents do not generally preclude lubricant from flowing out of, or leaking from, the motor vehicle axle assembly, transmission or transfer case cavity onto the ground. This is particularly the case when the lubricant expands in volume due to, for example, foaming of the lubricant, air being retained in the lubricant, volumetric expansion of the lubricant due to elevated operating temperatures, pumping or splashing of the lubricant resulting from internal rotating or moving parts, flow of the lubricant due to tilting of the motor vehicle, and thus the motor vehicle axle assembly, transmission and transfer case, and/or acceleration or deceleration of the motor vehicle.
A preferred embodiment of the present invention is, therefore, directed to interconnected vents for a motor vehicle axle assembly, transmission or transfer case which interconnects multiple vents at different locations together with another vent positioned at the highest point the lubricant travels. This allows lubricant to flow out of one vent and return to the other vent without leaking onto the ground. Such an interconnected vent arrangement will minimize the extent of external lubricant leakage due to such factors as foaming of the lubricant, air entrapment in the lubricant, volumetric expansion of the lubricant due to elevated operating temperatures, pumping or splashing of the lubricant by internal rotating or moving parts, flow of the lubricant due to tilting of the motor vehicle, and thus the motor vehicle axle assembly, transmission and transfer case, and/or acceleration or deceleration of the motor vehicle.
Other advantages and novel features of the present invention will become apparent in the following detailed description of the invention when considered in conjunction with the accompanying drawings.